Application: Real-time Environment Sensors for Trains
Modern rail
systems are a marvel of engineering and coordination. Not only are
trains expected to arrive and depart on time, but for safety and control
reasons, each car must remain in constant contact with the central
control center. In fact, some rail companies now go one step further
and provide passengers with ready access to the current time and environmental
conditions.
In the example described here, each car in the train has separate
temperature and humidity sensors connected directly to an Ethernet
network. The sensor values are transmitted in real time to the central
control center, which uses the information to manage the heating and
cooling system in the cars. In addition, the current time is flashed
on LCM screens so that passengers can keep track of the train's progress.
For
this application, Moxa's NPort 6000 secure device servers are arranged
in a ring topology. One NPort is installed in each of the cars, and
the Ethernet ports of adjacent NPorts are connected together. To the
complete the ring, the two end NPorts connect directly to each other.
The fact that each NPort has two Ethernet ports makes this type of
topology possible.
The ring network is configured to use Moxa's proprietary Turbo Ring
protocol, which supports a reconnection time of less than 100 milliseconds.
